Electric lamp.



A. P. MOARTHUR. SLEGTR LAMP. MPLIUATIOX FILED 00129. 1905.

Nofsmlo.

MUARTEUR.

ELECTRIC LAMP.

PPLIGATION FILED OSTA), 1905.

2 SHEETS-SHBBT 2.`

PATENTE) oorfls, 1907.

NETE@ I ALEXANDER P. MCARTHUR, ORANGE, NEW JERSEY.

Ennesimo LAMP.

Specification of Letters Petent.

Patented Got. l5, 19137 Application iilerl Dotobr 9, 19135. Scriel No. $1,911.

To all whom 'it may concern:

Be it known that I, ALEXANDER vP. Mon'rrrUn, a citizen of the United States, residing at Orange, 'in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Electric Lamps, of which the following is a specification` This invention relates particularly to electric lamps in which a reflecting device is arranged adjacent to the filament or other light-giving translating device, as will be hereinafter more fully set forth.

The object of this invention is to produce a simple and economical lamp of great efliciency.

i 'To this end the invention consists in the fee-tures of construction hereinafter described and claimed.

in the accompanying drawings-Figure l is s side elevation, partly in section, of o. lamp embodyingy my invention; Fig. 2 a plan view, partly in section, or' the lamp shown in Fig. l; Fig. 3 a view similar to Fig. l, showingY another iorm of my improved lamp; FigA fi a transverse section, taken on line 4 4 of Fig. 3, and Figs.v 5 and 6 are side elevations of one form` o1 my lamp showing the process of manufacture.

In the drawings I have shown my invention as applied to au ordinary forni of incandescent lamp; but it is not limited in its application to a lamp of this type, since, as may be readily understood, it may be applied :to an arc lamp or to any other orm of lampe-it being only necessary to arrange the reflecting devices and the light-giving element in proper relation, as ivill be hereinafter described.

As is .vell known, e. great part of the light rays in the 4ordinary form of lamp are lostthrough dispersion. .fit-

tempts have beenmede to collect and concentrate the rays by various means. such as shades and reflectors applied to the lamp, exterior, to the globe or bulb. It has also been proposed to place a reflector within the globe or bulb. Both of these devices, es hitherto employed, are open to serious objections-the first due to the loss of light, owing to the dstnnce between the re flectorand the light-giving element and the consequent necessity of employing polished or otherwise specially prepared reflecting surfaces. together with the loss in efliciency arisingy from the accumulation of dustand dirt on these surfaces, The second form is also objectionable, because of the small reflecting; surface which is rendered necessary by reason of the location oi the reflector .vithiu the globe or bulb, and the consequent inefiicient correction of the evil of dispersion.

Coming now Lo my invention-in the drawings c represents an ordinary incandescent globe; c is the stem of the lamp supporting the filaments b; a is a reflecting device supported upon the stein or' the lamp and in close proximity to the filament b, or other light-giving translating device.

Although it is preferable ordinarily io support the reflector on the stem o the lamp, do not wish to be limited to this precise form, for the reason that it may be supported at the bottom. or side ot the lamp in any desired manner iorthe purpose ol directing the rays of light in different directions.

The reflector is usually made o pressed gloss, and may be made of a Haring shape-as shown in Fig. le or in the shape of an inverted cone, as shown in Fig'fS. It will of course be understood that it may be made in other shapes i1" desired. It will be observed thatono Surface of this reiector is smooth, while the other surface is provided with a series of prisms. These prisms muy be arranged spirally and in. staggered relation, as shown in Fig. 2, or in any preferred form. 1n "Fr-rs. 3 and 1 I have shown them as straight. t will be fue ther obscrvcd that thc filament, or light-giving translating dev, e, is arranged adjacent the smooth sui-hice of thc reflector. It is in this particular relation of the reflector andthe light-giving clement that the gist oi my invention liesA One very important advantage arising from this arrangement is that l am enabled Lo 'dispense with the lining forming a reflecting surface, ,ordiiinrily employedv in lamps of this type. At the seme time the cliiciency of the lamp is very highly increased by placing the smooth surface next to the light-giving element, since the greater part of tlic rays are retracted by the prisznatic surfaces and turned back in the right directioni This result docs not follow when the prismatic surfaces are placed next tho light-giving element; and it will be readily und crstood by one skilled in optics that it cnnnot follow from such arrangement; because the light will bc dispersed by the prisms, as if no re ,Hector were present. By placing the reflector Within tbe lamp, the rays arc collected and turned in the usen ful direction prior to any dispersion taking place by reason of the rays of light having to poss :rnd rc-pnss through thc glass bulb, as is necessary with all shades. This very materially incrcnscs tho efficiency asthc rays pass through the glass bui once. I have 'found in actuel practice thnt the gain in cflcicncy from the use of my device is such that an eight cnndlc power lmnp containing this device will do thc wor-l: of u sixteen candie power lamp oi ordm-ry form.

In constructing my lamp, I rst blow a bulb of-a diameter sufficient to pci-mit thc reflector to bc placed within it and hold in position, and thon press thc cud of the bulb While hot around thc .neck of thc rctlector. This operation is clearly shown in Figs. 5 and f5 of thc drawings. ln Fig. 5 I'. is the ond of a blow pipe of a diameter sufiicieutly largo to admit the reiiector; and e is the bulb, which is shown in Fig. 5 before being pressed around the neck rl of the reflector and in Fig. alter this operation has taken place and the neck h formed thereon,

(lli

Having now doscrlwd my invention, what I claim as new 11ml iusirr' tu Svi-uw lly Lviiors Patent is:

1. hl un clwlriv lump. flw (-mnlninntion of :l hull) or il1-. 

